1. Field of the Invention
The present invention relates to a radio selective calling receiver and more particularly to a radio selective calling receiver having an infrared-ray communication function in use for communication with an external information terminal with an infrared-ray in addition to receiving radio selective call signals.
2. Description of the Related Art
Some conventional radio selective calling receivers have functions to output reception information or a fixed-type message which has been registered to an external data terminal by means of an infrared ray and to input information from the external data terminal in addition to an original radio selective calling receiving function. In such a conventional radio selective calling receiver having the infrared-ray communication function, a message or the like is transferred for a communication with an external data terminal independently of an operation of a radio section.
In addition, in the conventional radio selective calling receiver, a boosting circuit for boosting a primary supply voltage such as a dry cell is used to drive an infrared-ray emitting element; consumed current of an infrared-ray interface section comprising the infrared-ray emitting element and the driving circuit is extremely greater than consumed current of other circuits. A communication with the external data terminal is independent of a receiving operation of the radio section as described above, so that independent communication processing is performed based on telecommunication dispatching of an infrared-ray data communication.
In this conventional radio selective calling receiver, however, there is a problem that, if an infrared-ray data communication is performed during a receiving operation of the radio section, or if the receiving operation of the radio section is started during an infrared-ray data communication, an operation of the infrared-ray interface section causes a great fluctuation of the consumed current of the primary power supply, whereby a noise is generated by the boosting circuit and as a result a reception sensitivity of the radio section is significantly degraded due to the noise. Accordingly, in Japanese Patent Application No. 64964/95, to solve the above problem, there is disclosed a radio selective calling receiver having an infrared-ray data transmission function, comprising a memory for storing reception information received by a radio section, an infrared-ray data transmitting section for outputting input data to an external terminal by means of an infrared ray, an infrared-ray data transmission control section for controlling data transmission so that the reception information can be transmitted from the infrared-ray data transmitting section while also transmitting the reception information stored in the memory to the infrared-ray data transmitting section at an occurrence of a transmission dispatching operation from the external terminal, and a control means for controlling the transmitting operation in the infrared-ray data transmitting section so as to be stopped during an operation of the radio section.
According to the above-described prior application, it is possible to prevent a reception sensitivity in the radio section from being degraded by stopping the transmitting operation in the infrared-ray data transmitting section during an operation of the radio section since it prevents the operation of the radio section and the infrared-ray data transmitting operation from overlapping each other, which removes an effect of the noise given to the radio section by the boosting circuit during the infrared-ray transmitting operation.
The problem, however, occurs such as a degraded reception sensitivity of the radio section which occurs during the infrared-ray data transmission as described above also when infrared-ray data is received from the external data terminal during a receiving operation of the radio section.